Hubert Umberto Johnson, 20, of Lexington was arrested at 11:44 p.m. Saturday, after the death of the unidentified man found in the blaze.
According to a Lexington police arrest citation, Johnson said he hit the man with a "metal instrument" and with his fists several times.
The victim was found in a burning house at 115 Alabama Avenue at 10:26 a.m. Saturday, police said. He had suffered injuries "not associated with the fire," Fayette County Coroner Gary Ginn said Saturday.
The coroner's office said the victim's identity will probably be released this morning. The body was sent to the Medical Examiner's Office in Frankfort.
Neighbors saw smoke coming from the house and called the fire department, said Battalion Chief Steven Sea of the Lexington fire department. The victim died at the University of Kentucky Hospital.
